VL53L5CX gasket requirements with cover window and large air gap

[MFabb.1]

As exposed in the Application Note AN5231 of the VL53L1CX, a gasket may be required to limit the negative crosstalk effect if a cover window and a large air gap were both present.

 

Is there any similar Application Note specific for the VL53L5CX model?

For example, the following specifications can be considered:

• VL53L5CX with window cover
• PCB and window are parallel to each other
• PCB to cover window distance = 3mm
• window thickness = 0.5mm
• ranging distance from 20mm to 1000mm

Could a gasket be required in these conditions?

Thank you

[John E KVAM]

Any time the air gap goes above 0.5mm a gasket or other measure is going to be required.

And if you account for get different size of the sensor, then all the information in that app note still holds.

You are going to need an opaque bit of material to prevent the light from getting from the Tx side to the Rx without going out into the world.

I saw one guy build a structure like this oneThe depression in the underside (bottom pic) fits tightly over the sensor. The beveled holes on the top fit the field of view.

The trick is to make it of opaque (to 940nm light) and tight fitting.

I saw another use compressible 'rubber' (actually it was carbon infused silicon) to make a more traditional gasket. Not sure how the gasket was held in place though.

[MFabb.1]

Thank you John.

Could you provide also the link to the above structure?